An PLC splitter is a passive optical device that can split an input optical signal into multiple output optical signals, and is widely used in passive optical fiber networks. According to different working principles, PLC splitters are divided into PLC optical splitters (planar waveguide optical splitters) and FBT couplers (fused taper optical splitters). This article will aim to give you a clearer idea of the detailed differences between them.
First of all, before understanding the difference between PLC splitter and FBT coupler, let's briefly understand these two optical splitters.
The PLC splitter is fabricated by semiconductor technology and can provide a good solution for larger split configuration applications. PLC splitters are fabricated by photolithography on a quartz glass substrate with waveguides that can route a specific percentage (equivalent) of light. Usually, the optical division ratio of PLC splitter is 1x2~1x128/2x128~2x128/1x3/1x5/1x6/1x9/1x12, etc., with Bare fiber PLC Splitter(250um), Mini Type PLC Splitter(900um), ABS Type PLC Splitter, PLC Splitter with fan-out kits, LGX Type PLC Splitter, 1U Panel PLC Splitter, ODF Type PLC Splitter and other packages.
The FBT coupler adopts traditional passive device fabrication technology, which bundles two or more fibers together and realizes melting and drawing through a cone-pulling machine. Since the spliced optical fiber is relatively fragile, a glass tube made of epoxy resin and silica is usually covered outside the spliced optical fiber. At the same time, a layer of stainless steel tube is covered outside the glass tube, and finally sealed with silicon. With the mature development of technology, the cost-effectiveness of FBT coupler is getting higher and higher.
The working wavelength of the PLC splitter is 1260nm ~1650nm, and the wavelength can be adjusted to support more application environments; while the FBT optical splitter coupler only supports three wavelengths of 850nm/1310nm/1550nm and cannot work at other wavelengths .
The splitting ratio refers to the ratio of the input optical signal to the output optical signal of the optical splitter. The splitting ratio of PLC optical splitter is as high as 1:64, while the splitting ratio of FBT optical splitter is 1:32. Relatively speaking, PLC optical splitter can provide higher reliability. But the optical division ratio of FBT optical splitter is variable and supports customization, such as 1:3/1:5/1x6/1:9/1:12, while PLC optical splitter can only choose 1xn /2xN standard product.
The PLC optical splitter can achieve equal-ratio uniform splitting, while the FBT optical splitter is made up of multiple 1x2 connections. It lacks signal management and cannot achieve uniform splitting. Moreover, the larger the splitting ratio, the worse the uniformity, which affects the transmission distance.
At present, the mature taper drawing process can only pull less than 1x4 at a time. Therefore, when the splitting ratio is greater than 1:8, the FBT coupler needs more than 7 1x2 connection packages, which is prone to errors and failures. That is to say, the greater the splitting ratio of the FBT coupler, the greater the failure rate. The failure rate of PLC optical splitter is much smaller than that of FBT coupler, as shown in the figure below.
Temperature is a key factor affecting the insertion loss of optical devices, therefore, the stability of temperature plays a crucial role in the performance of the device. The PLC splitter can work stably at -40~85℃, while the working temperature range of the FBT coupler is -5~75℃. Relatively speaking, the PLC splitter has a wider working temperature range. It also maintains good performance in the environment.
The PLC optical splitter has a complex manufacturing process and high chip cost; while the FBT coupler is made of steel, heat shrinkable tubes and other materials. Due to the low material cost and simple device manufacturing technology, relatively speaking, FBT coupler are cheaper.
In short, PLC splitter and FBT coupler have their own advantages and disadvantages, as detailed below:
| Item | PLC Splitter | FBT Coupler |
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In general, PLC splitter and FBT coupler have many differences in manufacturing process, operating wavelength, temperature, etc. except for the similar appearance and size. From the advent of the PLC splitter, it can be seen that the manufacturing technology of the optical splitter has made great progress in recent years. Compared with the traditional FBT coupler, the PLC splitter is a passive source with superior performance. Optical components, if your network has high performance, it is recommended that you choose PLC splitter instead of FBT optical splitter coupler.